Improve

Author: 0x5bfa

src/Files.App.CsWin32/Windows.Win32.ComPtr.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Runtime.CompilerServices;
 using Windows.Win32;
+using Windows.Win32.Foundation;
 using Windows.Win32.System.Com;
 
 namespace Windows.Win32
@@ -39,11 +40,19 @@ public ComPtr(T* ptr)
 		}
 
 		[MethodImpl(MethodImplOptions.AggressiveInlining)]
-		public readonly ComPtr<U> As<U>(Guid riid) where U : unmanaged
+		public readonly ComPtr<U> As<U>() where U : unmanaged
 		{
-			ComPtr<U> pNewPtr = default;
-			((IUnknown*)_ptr)->QueryInterface(&riid, (void**)pNewPtr.GetAddressOf());
-			return pNewPtr;
+			ComPtr<U> ptr = default;
+			Guid iid = typeof(U).GUID;
+			((IUnknown*)_ptr)->QueryInterface(&iid, (void**)ptr.GetAddressOf());
+			return ptr;
+		}
+
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public readonly HRESULT CoCreateInstance<U>(CLSCTX dwClsContext = CLSCTX.CLSCTX_LOCAL_SERVER)
+		{
+			Guid iid = typeof(T).GUID, clsid = typeof(U).GUID;
+			return PInvoke.CoCreateInstance(&clsid, null, dwClsContext, &iid, (void**)this.GetAddressOf());
 		}
 
 		[MethodImpl(MethodImplOptions.AggressiveInlining)]

src/Files.App/Services/Windows/WindowsWallpaperService.cs

@@ -17,17 +17,9 @@ public sealed class WindowsWallpaperService : IWindowsWallpaperService
 		/// <inheritdoc/>
 		public unsafe void SetDesktopWallpaper(string szPath)
 		{
+			// Instantiate IDesktopWallpaper
 			using ComPtr<IDesktopWallpaper> pDesktopWallpaper = default;
-			var CLSID_DesktopWallpaper = typeof(DesktopWallpaper).GUID;
-			var IID_DesktopWallpaper = typeof(IDesktopWallpaper).GUID;
-
-			HRESULT hr = PInvoke.CoCreateInstance(
-				&CLSID_DesktopWallpaper,
-				null,
-				CLSCTX.CLSCTX_LOCAL_SERVER,
-				&IID_DesktopWallpaper,
-				(void**)pDesktopWallpaper.GetAddressOf())
-			.ThrowOnFailure();
+			HRESULT hr = pDesktopWallpaper.CoCreateInstance<DesktopWallpaper>().ThrowOnFailure();
 
 			// Get total count of all available monitors
 			hr = pDesktopWallpaper.Get()->GetMonitorDevicePathCount(out var dwMonitorCount).ThrowOnFailure();
@@ -51,37 +43,27 @@ public unsafe void SetDesktopWallpaper(string szPath)
 		/// <inheritdoc/>
 		public unsafe void SetDesktopSlideshow(string[] aszPaths)
 		{
+			// Instantiate IDesktopWallpaper
 			using ComPtr<IDesktopWallpaper> pDesktopWallpaper = default;
-			var CLSID_DesktopWallpaper = typeof(DesktopWallpaper).GUID;
-			var IID_DesktopWallpaper = typeof(IDesktopWallpaper).GUID;
-
-			HRESULT hr = PInvoke.CoCreateInstance(
-				&CLSID_DesktopWallpaper,
-				null,
-				CLSCTX.CLSCTX_LOCAL_SERVER,
-				&IID_DesktopWallpaper,
-				(void**)pDesktopWallpaper.GetAddressOf())
-			.ThrowOnFailure();
+			HRESULT hr = pDesktopWallpaper.CoCreateInstance<DesktopWallpaper>().ThrowOnFailure();
 
 			uint dwCount = (uint)aszPaths.Length;
 			ITEMIDLIST** ppItemIdList = stackalloc ITEMIDLIST*[aszPaths.Length];
 
-			// Get array of PIDL from the selected image files
+			// Get an array of PIDL from the selected image files
 			for (uint dwIndex = 0u; dwIndex < dwCount; dwIndex++)
 				ppItemIdList[dwIndex] = PInvoke.ILCreateFromPath(aszPaths[dwIndex]);
 
-			// Get a shell array of the array of the PIDL
+			// Get an IShellItemArray from the array of the PIDL
 			using ComPtr<IShellItemArray> pShellItemArray = default;
 			hr = PInvoke.SHCreateShellItemArrayFromIDLists(dwCount, ppItemIdList, pShellItemArray.GetAddressOf()).ThrowOnFailure();
 
-			// Set the slideshow
-			hr = pDesktopWallpaper.Get()->SetSlideshow(pShellItemArray.Get()).ThrowOnFailure();
-
-			// Free the allocated PIDL
+			// Release the allocated PIDL
 			for (uint dwIndex = 0u; dwIndex < dwCount; dwIndex++)
-				PInvoke.ILFree(ppItemIdList[dwIndex]);
+				PInvoke.CoTaskMemFree((void*)ppItemIdList[dwIndex]);
 
-			// Set wallpaper position to fill the monitor.
+			// Set the slideshow and its position
+			hr = pDesktopWallpaper.Get()->SetSlideshow(pShellItemArray.Get()).ThrowOnFailure();
 			hr = pDesktopWallpaper.Get()->SetPosition(DESKTOP_WALLPAPER_POSITION.DWPOS_FILL).ThrowOnFailure();
 		}